are you ready to go the concert ?   yes . Should we go there by bus so we aren't late ?   actually , why don't we go there by bike ? We could get stuck in traffic if we travel by bus in such hour .   that's true . Cycling is good for our environment , too . Let me just get my helmet then .   is your helmet comfortable ?   not really , but I liked the design , so I got it .   maybe you should think about getting a round helmet ; they're better .   I'll think about it .   is that your new bicycle ?   yes , my father gave it to me for my birthday . Do you like it ?   it's the newest 10 speed cycling mountain bike . These are really expensive !   nothing but the best from my dad . I like everything about it except for the brakes . They are a bit sticky .   I can fix those for you . Is there anything else wrong with it ?   well , my saddle is too low for me . Do you know how to change the height ?   that's easy . It's important to have the saddle high enough so that your legs can extend fully when you are on your bicycle .   is that why my knees have felt sore after every time I've ridden my bike ?   it's possible . Give me a minute and I can fix these for you and then we can go . 